In general, rapid prototyping refers to a conventional manufacturing process used to make parts, wherein the part is built on a layer-by-layer basis using layers of hardening material. Per this technology, the part to be manufactured is considered a series of discrete cross-sectional regions which, when combined together, make-up a three-dimensional structure. The building-up of a part layer-by-layer is very different than conventional machining technologies, where metal or plastic pieces are cut and drilled to a desired shape. In rapid prototyping technology, the parts are produced directly from computer-aided design (CAD) or other digital images. Software is used to slice the digital image into thin cross-sectional layers. Then, the part is constructed by placing layers of plastic or other hardening material on top of each other. There are many different techniques that can be used to combine the layers of structural material. A curing step may be required to fully cure the layers of material.
One issue related to bottom up technique, such as employed in B9Creator from B9Creations, LLC, Form1 from Formlabs, etc., requires the separation of cured solid from the bottom clear window in a vat, which often showed to be difficult and required extra care and step. Irradiation is needed to stop to separate cured solid from the bottom clear window in a vat before next layer can be built.